It is generally known that the anticancer activity of Mycobacterium tuberculosis is attributable to active agents in the cytoplasmic membrane thereof, particularly the polysaccharide and lipid derivatives.
For instance, Azuma et al. succeeded in isolating N-acetylmuramyl-L-alanyl-D-isoglutamin(MDP) which is an active component of M. tuberculosis [Azuma, L. et al., J. Bact., 96, 1885-1887(1968)].
Barnes et al., on the other hand, reported that lipoarabinomannan promotes the production of cytokin [Barnes, P. F. et al., J. Immunol., 149, 541-547(1992)]. Chung et al. isolated from M. tuberculosis a substance having an anticancer activity and used this substance, designated as Tubercin-3, in treating terminal-cancer and leprosy patients as well as laboratory animals suffering from tumoral symptoms [Chung, T. H., J. Korean Med. Ass., 17, 427-431(1974); Chung, T. H. et al., Yonsei Med. J., 17, 131-135(1976)].
On the other hand, a person infected by M. tuberculosis bacilli normally exhibits granulomatous inflammation, and if the infected site is lung, cavity formation progresses together with an inflammatory reaction, induced by secretion of proteins and glycolipids originally present in the cell wall of M. tuberculosis. This suggests that, in case high molecular-weight polysaccharides or proteins are used in cancer immunotherapies, it may be difficult to suppress such adverse side effects as undesirable immuno-responses and uncontrollable inflammatory reactions.